Valve and method for producing a valve

ABSTRACT

A valve and a method for producing a valve, in particular for coolant circuits, having a valve seat ( 2 ) including a valve seating element ( 1 ) for a valve body ( 3 ), by stamping the pole shoe to form at least one sealing surface ( 8 ) to avoid the disadvantages of the prior art This is achieved according to the invention by forming at least one sealing surface ( 8 ) to form a novel sealing element ( 1 ) by utilizing a stamping element to form a stamped surface of the novel valve with a valve seating element.

BACKGROUND OF THE INVENTION

(1) Field Of The Invention

The invention relates to a valve and a method for producing a valvehaving a valve seat with a valve seating element. More particularly thenovel valve and method for producing the valve includes a stamped outvalve seating surface.

(2) Description of Related Art Including Information Disclosed Under 37C.F.R. 1.97 and 1.98

At present, a wide variety of valves are commercially available. Forexample, electromagnetic valves, in particular bistable valves, existand can be used in various applications, for example in fluid circuitsof domestic appliances such as refrigerators or for steam expansion fordrinks machines, such as coffee machines for example, but also anotherareas such as in the area of analytics or measuring technology.

In most application areas, such as for instance the application area ofdomestic appliances, valves which are of a compact design are preferredthat can also be produced and fitted with as little effort as possible.To satisfy these requirements, various developments have already becomeknown (cf. DE 199 14 972 A1 or WO 03/071 176 A1).

Known valves have, inter alia, a valve seat, which are sealed by a valvebody to ensure the function of the valve. For example in the case ofball valves, a spherical valve seat is accordingly required. For sealingthe valve seat, an elastomer seal or the like may be used for example.

In addition, metallic seals may also be used in certain applications.The use of correspondingly metallic, spherical sealing seats requiresvery precise and uncontaminated production and fitting of the valve.Corresponding valve seats, in particular in the case of valves witharmatures, are often hardened after turning on a lathe, producing acertain hardening distortion. In the case of some certain valves, thepole shoe comprising the valve seat may be covered with copper or thelike after hardening, so that subsequent soldering of the pole shoe canbe advantageously realized. Even with this copper coating, inaccuracieswith respect to the form of the valve seat can occur, and may lead tothe valve leaking during operation.

In addition, particles of dirt can contaminate the valve seat bothduring the production of the valve seat and during the fitting of thevalve, which in turn can lead to the valve seat leaking duringoperation.

The object of the invention is to propose a valve and a method forproducing a valve with which the aforementioned disadvantages of theprior art are reduced or avoided.

BRIEF SUMMARY OF THE INVENTION

The object of the invention is achieved by the method of the inventionto produce the novel valve by stamping a stamped surface of at least onesealing surface to provide a valve having at least a part of the sealingsurface stamped.

Advantageous embodiments and developments of the invention are possibleby utilizing a stamping element that corresponds to the sealing surfaceof the valve body, utilizing a stamping element to form a partlyspherical surface to form the valve seating element, forming at leastone recess on the stamping surface of the valve seating element beforestamping, forming the recess by turning, forming the recess so that itat least conforms to at least a part of the valve body, providing atleast one ridge and more specifically an annular web on the valveseating element by forming or cutting methods, providing a stampinggauge, utilizing a spherical valve body having a stop surface for thestamping gauge and/or permanent magnet and/or spacing element, havingthe valve seating element form a wall of the valve chamber, forming thevalve seating element as a pole shoe, providing an additional sealbetween the valve body and seating element and providing at least onegroove in the valve seating element for the seal.

Accordingly, the production method according to the invention isdistinguished by the fact that at least one sealing surface of a sealingelement is formed by means of a stamping element by stamping a stampingsurface or by the fact that the valve has an at least partly stampedsealing surface for the valve body.

With the aid of a correspondingly advantageous stamping element, asealing surface of almost any desired form, in particular athree-dimensionally formed sealing surface, can be produced with veryhigh accuracy. A correspondingly high accuracy ensures particularlytight sealing of the valve seat by the valve body, which significantlyincreases the operational reliability of the valve.

Furthermore, stamping represents a shaping, non-cutting method whichsignificantly reduces the risk of contaminating the valve seat duringits production in comparison with the prior art. Moreover, a certainstrengthening of the material in the region of the sealing surface canbe brought about by the cold forming that accompanies the stamping,which has a positive effect on the service life of the valve. Inaddition, dimensional inaccuracies of previous production steps, such asfor example the turning on a lathe, can be compensated for or eliminatedwith the aid of the stamping operation.

A stamping element of a form which corresponds at least partly to theform of the valve body is preferably used. This allows finishingoperations on the sealing surfaces to become superfluous to the greatestextent. For example, the portion of the stamping element that stamps thevalve seat can be formed conically and/or spherically in a waycorresponding to the desired form of the valve seat. Specifically valveseats that are correspondingly formed three-dimensionally can be formedparticularly cost-effectively in high numbers by the stamping methodaccording to the invention.

In a preferred embodiment and best mode of the invention, a sealingelement that is separate from the component having the valve seat,referred to hereafter as the valve seating element, and comprises thestamping surface, i.e. the surface to be stamped or the sealing surfaceproduced by the stamping, is used for sealing the valve seat. Ifappropriate, this element may be let into the valve seating element as asleeve or the like with the aid of a corresponding recess.

However, the sealing surface is preferably at least partly formeddirectly into the valve seating element. This achieves a reduction inthe number of components that are used in comparison with the previouslymentioned variant, whereby the effort involved in production is reduced.

Advantageously, a projection which comprises the stamping surface isprovided before the stamping. In this case, the projection may be both aseparate element or a protruding part of the valve seating element. Theprojection is generally deformed at least partly by the stampingoperation in such a way that the amount by which the projection extendsis reduced or largely eliminated.

At least one recess comprising the stamping surface is advantageouslyproduced, in particular in the valve seating element, before thestamping operation. In a special development of the invention, therecess is formed as a recess of the valve seating element produced by aturning method. A correspondingly produced recess of the valve seatingelement can be cost-effectively produced particularly well according tothe invention. A comparatively low dimensional accuracy of the recess ismade possible here in particular by the fact that the final shaping issubsequently produced by the stamping according to the invention withhigh dimensional accuracy.

In the case of a spherical valve seat, the recess is advantageouslyprovided at least in certain regions with a somewhat greater radius thanthe radius of the valve body. With the difference between the radii, itis possible in particular to perform an adaptation of, or make anallowance for, the measuring inaccuracy of the production of the recess.

In an advantageous variant of the invention, the recess is formed atleast partly in the form of the valve body. As a result, a comparativelylarge sealing surface can be produced with a comparatively smallstamping volume to be deformed, i.e. the volume of material that is tobe deformed by the stamping. A correspondingly large sealing surfaceleads to particularly good sealing of the valve seat by the valve body,which increases the operational reliability of the valve. Furthermore,according to this variant of the invention, the recess can undertake acertain guiding function for the valve body during the operation of thevalve.

At least one projection to be stamped of the valve seating element isadvantageously produced during the production of the recess. Forexample, the formation of the recess has a difference in volume withrespect to the form of the valve body, which substantially forms theprojection. This difference in volume is eliminated by the stampingoperation, to the extent to which it approximately corresponds to theprojection, with the sealing surface according to the invention beinggenerated in an advantageous way.

The projection is advantageously formed as an annular web. Acorresponding annular web can be produced in a particularly simplemanner for example with the aid of cutting methods, for example byturning on a lathe or the like.

As already stated above, the recess and/or the projection is preferablyproduced at least partly by forming and/or cutting methods. Inparticular in the case of circular valve seats, the already mentionedturning methods are particularly of advantage.

Preferably, at least one stamping gage with at least one stop forstopping against the sealing element and/or valve seating element isused. The stamping element is advantageously arranged between thestamping gage and the sealing element and/or the valve seating elementduring stamping. With the aid of a corresponding stamping element, aparticularly high dimensional accuracy can be advantageously realized,in particular in mass production. In addition, a particularly highaccuracy, including of the length of stroke of the valve body duringoperation, is achieved by the high accuracy of the position of thesealing surface or of the valve seat, in particular when viewed in thedirection of the stroke of the valve body or the direction of the valveaxis, that can be achieved by means of the stamping element. A highaccuracy of the stroke of the valve body is of particular significancefor the operational reliability of the valve.

Furthermore, the position or the distance of a stop for magnets, inparticular permanent magnets, with respect to the sealing surface orwith respect to the valve seat can be set for example with particularlyhigh accuracy by the stamping element. This dimension is of greatrelevance in particular for the force of attraction of the valve body atthe valve seat.

At least one stop surface for the stopping of a stamping gage, apermanent magnet and/or a spacing element for setting a stroke of thevalve body is advantageously provided, it being possible in aparticularly advantageous development of this embodiment for only onestop surface to be provided for a number of or all the aforementionedfunctions. In the case of the last-mentioned multifunctional variant ofthe stop surface according to the invention, the structural complexityof the valve is reduced, which in turn leads to particularly low-costproduction.

In an advantageous embodiment of the invention, the valve seatingelement comprises a wall of a valve chamber. The valve seating elementis preferably formed as a pole shoe. Such measures can lead to aparticularly simple or structurally less complex realization of thevalve according to the invention, which further reduces the productioncosts.

A separate seal made of compliant or elastic material, for example aplastic seal, in particular an elastomer seal, Teflon seal or the like,is advantageously arranged between the valve body and the sealingelement. For this purpose, the valve seating element may for example beprovided with at least one groove for receiving the seal. Such measuresallow the tightness of the seal of the valve seat to be additionallyincreased, which contributes to the improvement in the operationalreliability of the valve.

BRIEF VIEW OF THE SEVERAL VIEWS OF THE DRAWING(S

An exemplary embodiment of the invention is represented in the drawingand is explained in more detail below on the basis of the figures, inwhich specifically:

FIG. 1 shows a schematic, sectioned representation of a valve seat to bestamped according to the invention and

FIG. 2 shows a schematic, sectioned representation of a stamped valveseat according to the invention.

DETAILED DESCRIPTION OF THE INVENTION INCLUDING BEST MODE

In FIG. 1, a pole shoe 1 is illustrated with a valve seat 2 and astamping element 16. Here, the state of the valve seat 2 immediatelybefore or during the stamping operation is shown. Before the stamping, arecess 4 of the pole shoe 1 or valve seating element 1 was produced,preferably by means of a turning method, thereby generating a projectionor an annular web 5, which comprises a stamping surface 17.

In FIG. 2, the valve seat 2 after the stamping operation isschematically represented. The deformation 6 of the pole shoe 1 wasproduced from the projection or annular web 5 by the stamping. Accordingto this figure, it is clear that the deformation 6 leads to aconstriction or bulging of the valve bore 7.

Furthermore, a sealing surface 8 was produced by the stamping of thevalve seat 2. The sealing surface 8 forms the contact surface betweenthe valve body 3 and the pole shoe 1. A spherical ring has been producedby the stamping as a sealing surface 8 which has a high accuracy of thespherical form with respect to the spherical form of the valve body 3.As a result, the recess 4 is advantageously adapted to the form of thevalve body 3, so that a particularly tight valve seat 2 is produced forthe valve body 3.

Also represented in FIG. 2 is a notch 9 in the pole shoe 1, which canoptionally be provided and is formed for receiving a seal, for examplean elastomer seal, Teflon seal or the like. A Teflon seal or elastomerseal 10, which may likewise be optionally provided, is additionallyshown. Both the elastomer seal 10 and the seal which can be placedand/or injection-molded into the notch 9 but is not shown any morespecifically may be provided under special conditions for the additionalsealing of the valve seat 2.

FIG. 2 also reveals a magnet 11, in particular an annular magnet 11.This magnet 11 is precisely localized at the pole shoe 1 with the aid ofa stop 12. The exact fixing of the position of the magnet 11 and of thesealing surface 8 has the effect of fixing the force of attractionproduced by this magnet for the valve body 3. This ensures that thevalve operates in a reliable way.

Furthermore, it is also clear in FIG. 1 that the stop 12 is additionallyformed as a stop 12 for a stamping gage 14 or the stop 13 of the latter.During the stamping operation, highly accurate fixing of the position ofthe sealing surface 8 in the axial direction 15 of the valve or in thedirection of the valve stroke of the valve body 3 is fixed with the aidof the stamping gage 14.

In the case of the production method according to the invention, it isgenerally of advantage quite particularly that the recess 4 can beproduced with comparatively low accuracy, including by turning methods.The inaccuracies of the turning on a lathe that exist in this case, bothwith regard to the form of the recess and with respect to the outerdimensions of the pole shoe 1 or the stop 12, etc., are reduced oreliminated in an advantageous way during the stamping, in particular onaccount of the stamping gage 14. The stamping gage 14 and/or thestamping element 16 are, for example, hardened elements, so that,specifically in the mass production of corresponding valve seats 2, ahigh accuracy of numerous valves according to the invention can berealized with low production costs.

In the case of valves according to the invention, a spacing elementaccording to the applicant's international patent application presentedin the prior art is used for example between two pole shoes 1. By meansof this spacing element, specifically in combination with the stampedvalve seat 2 according to the present invention, a valve which is highlyprecise, and consequently also provides a tight seal, can be produced ina simple way at low cost, so that it is even possible, depending on theapplication, to dispense with final testing or measuring of thetolerances of individual production steps and/or of the valve in itsfinally fitted form. The overall effort involved in the production andfitting of corresponding valves according to the invention isaccordingly reduced.

In principle, the stamping gage 14 may be produced with very highaccuracy by advantageous working of the stop 13, in particular bygrinding, polishing, etc. The same applies correspondingly to anabovementioned spacing element between the pole shoes 1.

List of Reference Numerals:

1 pole shoe

2 valve seat

3 valve body

4 recess

5 annular web

6 deformation

7 bore

8 sealing surface

9 notch

10 elastomer

11 magnet

12 stop

13 stop

14 gage

15 axis

16 stamping element

17 stamping surface

1. A method for producing a valve for coolant circuits, having a valveseat (2) forming a valve seating element (1) for a valve body (3)wherein the improvement comprises forming at least one sealing surface(8) of a sealing element (1) by means of stamping a valve seat or poleshow with a stamping element (16).
 2. The method according to claim 1,further comprising the step of utilizing a stamping element (16)corresponding to at least a part of the form of the valve body (3). 3.The method according to claim 1 wherein said step of utilizing saidstamping element includes forming at least partly a spherical sealingsurface (8).
 4. The method according to claim 1 wherein said stampingelement forms a valve seat (2) in the sealing surface (8).
 5. The methodaccording to claim 1 or 2 further comprising the step of forming atleast one recess (4) on the stamping surface (17) before the stampingoperation.
 6. The method according to claim 5 wherein the recess (4) isformed by a turning method as a recess (4) of the valve seating element(1).
 7. The method according to claim 5 wherein the recess (4) is formedso that it substantially corresponds to the form of the valve body (3).8. The method according to claim 1 further comprising the step ofproviding at least one projection (5) on the valve seating element (1)before the stamping operation.
 9. The method according to claim 8wherein the projection (5) is formed as an annular web (5).
 10. Themethod according to claim 1 further comprising the step of first forminga recess (4) and/or the projection (5) by forming and/or cutting methodsbefore said stamping operation.
 11. The method according to claim 1wherein said step of stamping is achieved with a stamping gage (14)having a stop (13) for stopping the stamping element against the valveseating element (1).
 12. The method according to claim 11 wherein saidstamping element (16) is arranged between the stamping gage (14) and thevalve seating element (1).
 13. A valve for coolant circuits, having atleast one valve seat (2) of a valve seating element (1) for a valve body(3) wherein the improvement comprises at least one partly stampedsealing surface (8) disposed on the surface of the seating element (1).14. The valve according to claim 13, wherein the valve seat element (3)is substantially concave.
 15. The valve according to claim 13 whereinsaid valve seat (2) was formed from a recess (4) in the valve seatingelement (1).
 16. The valve according to claim 13 wherein said seatelement includes at least one stop surface (12) for stopping a stampinggage (14) and/or holding a permanent magnet (11) and/or a spacingelement.
 17. The valve according to claim 13 wherein the valve seatingelement (1) forms a wall of a valve chamber.
 18. The valve according toclaim 13 wherein the valve seating element (1) is formed as a pole shoe(1).
 19. The valve according to claim 13 or 16 further comprising anadditional seal (10) disposed between the valve body (3) and the sealingelement (1).
 20. The valve according to claim 13 or 16 furthercomprising at least one groove (9) for receiving the seal (10) in thevalve seating element (1).
 21. A precision valve comprising: (a) a valvehousing having a substantially concave seating surface having a portionof said substantially concave seating surface deformed by stamping; (b)a passage disposed substantially perpendicular to said substantiallyconcave seating surface; (c) an opening communicating with said passageand said substantially concave seating surface said opening having astamped pressure deformation.